Sorry are having so much trouble. I had reverse replacement 3-months ago. I am 76 and have been a gymnast and weight lifter, to which I attribute the bone on bone and severe arthritis in my shoulders (both). Since the surgery, I did 10 weeks of PT three times a week - it helped, but I still have limited flexibility in terms of reaching behind my back - no improvement there. I have little to no pain, other than when I overextend behind me, but it is in the muscle. I returned to the gym after 2-months and after a slow start, I am at about 70% of what I was lifting before surgery, although with a lot of pain, now not so much.
Recovery was much different than when I had a hip replaced three years ago - that has been very successful - I leg press 500 pounds and have no pain.
My left shoulder has the same bone on bone and arthritis nodules as the right. The surgeon says I need to replace the left shoulder, it hurts doing certain motions. Will I do that? Not sure I will at this time ... maybe later, if the pain and mobility gets worse.
Just my take, I believe I was fortunate to be in good shape before the surgery.